Dinosaurs: This is probably not unusual in these parts, but as a kid I was obsessed with dinosaurs. Funnily enough that obsession was superseded by super-hero comics and D&D, but it was there. And for me, dinosaurs are an integral part of any D&D monster collection. Lost worlds filled with prehistoric creatures are a staple of the pulps that the game was founded on, and the game feels incomplete without them.
The entry begins with some information that applies to all the dinosaurs herein. It explains that because the D&D world is magical, all sorts of creatures that never existed together historically can do so here, on a strange plane, alternate world, or lost continent. All dinosaurs are stupid, motivated mostly by hunger. The carnivorous types will attack aggressively, while most herbivores ignore things they can’t eat unless threatened.
Dinosaurs first appeared in the wilderness encounter charts in OD&D. There are a lot covered here statistically, but not much space is given to describing them. With that in mind, I’m only doing a brief run-down myself. Keep in mind that they’re all really tough, with loads of hit dice, and that’s about all you need to know about their stats.
Anatosaurus: Duck-billed plant-eaters that run from attack.
Ankylosaurus: These are the rad dinosaurs with the spiked shell and heavy clubbed tail. They’re aggressive if threatened.
Antrodemus (Allosaurus): Apparently they’re fast, but no other physical description is forthcoming.
Apatosaurus (Brontosaurus): Big dinosaur, long neck, has to live in water to support its weight. Frequently eaten by Fred Flintstone.
Archelon Ischyras: Big marine turtles.
Brachiosaurus: A bigger brontosaurus.
Camarasaurus: A smaller brontosaurus.
Ceratosaurus: A bipedal carnivore with a horn on its nose.
Cetiosaurus: Another type of brontosaurus, with a slightly bigger head. Now I love dinos, but Gary’s getting a little redundant here.
Dinichtys: A very big fish that can swallow a man whole with a natural 20.
Diplodocus: A semi-aquatic type sort of similar to brontosaurus, and at least I remember this guy. They can submerge to a depth of 30 feet.
Elasmosaurus: Long-necked fish-like reptiles. They are carnivorous and aggressive.
Gorgosaurus: A sort of smaller T-Rex.
Iguanadon: A bipedal herbivore with incongruous thumb spikes. If memory serves, I don’t think dinosaur experts give this guy thumb spikes any more. But D&D is firmly rooted in the scientific theories of the 1970s, so science be damned! My Iguanadons have awesome thumb spikes with which they can jank other dinosaurs in the neck.
EDIT: Nope, I had it backwards. Scientists used to place the spikes on its head, until they figured out they were thumb spikes.
Lambeosaurus: A crested herbivore with very sharp senses.
Megalosaurus: Can walk on all fours or bipedally, and have very large jaws.
Monoclonius: Like a reptilian rhinoceros, with a shield of bone that covers their head and neck. They’ll trample smaller creature that irritate them.
Mosasaurus: Marine dinosaurs that can move very slowly on land with their flippers.
Paleoscincus: This guy is covered in armor plate and spines, with a spiked tail. Any predator that tries to eat one will take damage itself.
Pentaceratops: An aggressive plant-eater with a shield covering its head like the triceratops.
Plateosaurus: Another plant eater. They can walk on two legs to watch for predators, or run quickly on all fours.
Plesiosaurus: Aggressive marine dinosaur with a really long neck.
Pteranodon: The classic aerial dinosaur. They’ll swoop and try to carry prey away in their beaks, or just spear them. And don’t forget Marvel villain Sauron, who was transformed after being bitten by a pterodactyl. It would be pretty awesome to inflict one of my PCs with dinosaur lycanthropy. (Needless to say, that’s not mentioned in the book here.)
Stegosaurus: Ah, now we’re into the classics. An aggressive herbivore with plates along its back and a spiked tail.
Styracosaurus: Another aggressive herbivore with a plate protecting its head. Apparently this one has sharp frills that can cut anyone trying to bite it from behind.
Teratosaurus: A carnivore that runs really fast after anything that looks edible.
Triceratops: The classic shield-covering-the-head guy, with three spikes sticking out the front. They’re super aggressive, and likely to trample smaller creatures.
Tyrannosaurus Rex: Ah, classic. It even has an illustration depicting T-Rex standing completely upright, which is pretty old-school in dinosaur theories. Mostly these days they’re depicted with their heads lower to the ground. And I love the anecdote that these guys are so fierce, they’re likely to swallow the head of a triceratops and then slowly die as the horns pierce its stomach. They can swallow men on a roll of 18 or better.
The only popularly known dinosaur that's missing from here is the velociraptor. But you know, I don't remember seeing anything about those until the mid-90s and Jurassic Park. And the raptors in that movie were much larger than the historical version. I guess they just didn't have an impact on popular culture by the 1970s.